C++ 运算符=在两个std:：chrono:：time\u点之间导致错误
我有一个结构，其中包含一个C++ 运算符=在两个std:：chrono:：time\u点之间导致错误,c++,chrono,C++,Chrono,我有一个结构，其中包含一个std:：chrono:：system\u clock:：time\u point struct NetInfo { std::chrono::system_clock::time_point time; std::chrono::steady_clock::time_point start; }; 当我尝试将一个时间点分配给std:：chrono:：system\u clock:：now（）的结果时 我得到了这个巨大的错误 /home/roo
std:：chrono:：system\u clock:：time\u pointstruct NetInfo {
std::chrono::system_clock::time_point time;
std::chrono::steady_clock::time_point start;
};
std:：chrono:：system\u clock:：now（）的结果时
我得到了这个巨大的错误
/home/rootkid/rendu/cpp2/cpp_zia/lib/NetService/src/NetService.cpp:48:51: error: no match for ‘operator=’ (operand types are ‘std::chrono::_V2::steady_clock::time_point {aka std::chrono::time_point<std::chrono::_V2::steady_clock, std::chrono::duration<long int, std::ratio<1, 1000000000> > >}’ and ‘std::chrono::_V2::system_clock::time_point {aka std::chrono::time_point<std::chrono::_V2::system_clock, std::chrono::duration<long int, std::ratio<1, 1000000000> > >}’)
ni.start = std::chrono::system_clock::now();
^
In file included from /usr/include/c++/7.2.1/thread:38:0,
from /home/rootkid/rendu/cpp2/cpp_zia/lib/NetService/./include/NetService.h:3,
from /home/rootkid/rendu/cpp2/cpp_zia/lib/NetService/src/NetService.cpp:1:
/usr/include/c++/7.2.1/chrono:610:14: note: candidate: constexpr std::chrono::time_point<std::chrono::_V2::steady_clock, std::chrono::duration<long int, std::ratio<1, 1000000000> > >& std::chrono::time_point<std::chrono::_V2::steady_clock, std::chrono::duration<long int, std::ratio<1, 1000000000> > >::operator=(const std::chrono::time_point<std::chrono::_V2::steady_clock, std::chrono::duration<long int, std::ratio<1, 1000000000> > >&)
struct time_point
^~~~~~~~~~
/usr/include/c++/7.2.1/chrono:610:14: note: no known conversion for argument 1 from ‘std::chrono::_V2::system_clock::time_point {aka std::chrono::time_point<std::chrono::_V2::system_clock, std::chrono::duration<long int, std::ratio<1, 1000000000> > >}’ to ‘const std::chrono::time_point<std::chrono::_V2::steady_clock, std::chrono::duration<long int, std::ratio<1, 1000000000> > >&’
/usr/include/c++/7.2.1/chrono:610:14: note: candidate: constexpr std::chrono::time_point<std::chrono::_V2::steady_clock, std::chrono::duration<long int, std::ratio<1, 1000000000> > >& std::chrono::time_point<std::chrono::_V2::steady_clock, std::chrono::duration<long int, std::ratio<1, 1000000000> > >::operator=(std::chrono::time_point<std::chrono::_V2::steady_clock, std::chrono::duration<long int, std::ratio<1, 1000000000> > >&&)
/usr/include/c++/7.2.1/chrono:610:14: note: no known conversion for argument 1 from ‘std::chrono::_V2::system_clock::time_point {aka std::chrono::time_point<std::chrono::_V2::system_clock, std::chrono::duration<long int, std::ratio<1, 1000000000> > >}’ to ‘std::chrono::time_point<std::chrono::_V2::steady_clock, std::chrono::duration<long int, std::ratio<1, 1000000000> > >&&’
/home/rootkid/rendu/cpp2/cpp\u zia/lib/NetService/src/NetService.cpp:48:51：错误：与“operator=”不匹配（操作数类型为“std:：chrono:：_V2:：stable_clock:：time_point{aka std:：chrono:：time_point}和“std:：chrono:：：_V2:：system_clock:：time_point{aka std:：chrono:：time_point}”）
ni.start=std:：chrono:：system_clock:：now（）；
^
在/usr/include/c++/7.2.1/thread:38:0中包含的文件中，
来自/home/rootkid/rendu/cpp2/cpp_zia/lib/NetService//include/NetService.h:3，
来自/home/rootkid/rendu/cpp2/cpp_zia/lib/NetService/src/NetService.cpp:1：
/usr/include/c++/7.2.1/chrono:610:14：注：候选：constexpr std:：chrono:：time_point&std:：chrono:：time_point:：operator=（const std:：chrono:：time_point&）
结构时间点
^~~~~~~~~~
/usr/include/c++/7.2.1/chrono:610:14：注意：参数1从“std:：chrono:：V2:：system_clock:：time_point{aka std:：chrono:：time_point}”到“const std:：chrono:：time_point}”没有已知的转换
/usr/include/c++/7.2.1/chrono:610:14：注：候选：constepr std:：chrono:：time_point&std:：chrono:：time_point:：operator=（std:：chrono:：time_point&）
/usr/include/c++/7.2.1/chrono:610:14：注意：参数1从“std:：chrono:：V2:：system_clock:：time_point{aka std:：chrono:：time_point}”到“std:：chrono:：time_point&”没有已知的转换
你知道我做错了什么吗？虽然没有具体说明，但这是一个事实上的标准，系统时钟正在测量（大约自1970-01-01 00:00:00 UTC以来的持续时间），尽管每个平台的精度不同
稳定时钟
的时代也未明确，也没有形成事实上的标准。不同的平台做不同的事情。例如，在我的平台上，稳定时钟
测量计算机启动后的时间
旨在在编译时捕获尽可能多的逻辑错误。将系统时钟：：时间点
分配给稳定时钟：：时间点
将是一个逻辑错误，因为这两个时钟是针对不同的时代测量的
未来的标准可能会提供一种将一个时钟的时间点
转换或“转换”到另一个时钟的方法，但这并不是一个简单的任务。这需要考虑到不同时代的差异，进行一些计算。否则，时间点
将表示分配后与分配前不同的时间瞬间
tl；dr:编译器在编译时为您捕获了一个逻辑错误。开始
是一个稳定的时钟
时间点，如果您试图从系统时钟
时间点分配，则无法执行该操作。两种时间点类型都不同。
/home/rootkid/rendu/cpp2/cpp_zia/lib/NetService/src/NetService.cpp:48:51: error: no match for ‘operator=’ (operand types are ‘std::chrono::_V2::steady_clock::time_point {aka std::chrono::time_point<std::chrono::_V2::steady_clock, std::chrono::duration<long int, std::ratio<1, 1000000000> > >}’ and ‘std::chrono::_V2::system_clock::time_point {aka std::chrono::time_point<std::chrono::_V2::system_clock, std::chrono::duration<long int, std::ratio<1, 1000000000> > >}’)
ni.start = std::chrono::system_clock::now();
^
In file included from /usr/include/c++/7.2.1/thread:38:0,
from /home/rootkid/rendu/cpp2/cpp_zia/lib/NetService/./include/NetService.h:3,
from /home/rootkid/rendu/cpp2/cpp_zia/lib/NetService/src/NetService.cpp:1:
/usr/include/c++/7.2.1/chrono:610:14: note: candidate: constexpr std::chrono::time_point<std::chrono::_V2::steady_clock, std::chrono::duration<long int, std::ratio<1, 1000000000> > >& std::chrono::time_point<std::chrono::_V2::steady_clock, std::chrono::duration<long int, std::ratio<1, 1000000000> > >::operator=(const std::chrono::time_point<std::chrono::_V2::steady_clock, std::chrono::duration<long int, std::ratio<1, 1000000000> > >&)
struct time_point
^~~~~~~~~~
/usr/include/c++/7.2.1/chrono:610:14: note: no known conversion for argument 1 from ‘std::chrono::_V2::system_clock::time_point {aka std::chrono::time_point<std::chrono::_V2::system_clock, std::chrono::duration<long int, std::ratio<1, 1000000000> > >}’ to ‘const std::chrono::time_point<std::chrono::_V2::steady_clock, std::chrono::duration<long int, std::ratio<1, 1000000000> > >&’
/usr/include/c++/7.2.1/chrono:610:14: note: candidate: constexpr std::chrono::time_point<std::chrono::_V2::steady_clock, std::chrono::duration<long int, std::ratio<1, 1000000000> > >& std::chrono::time_point<std::chrono::_V2::steady_clock, std::chrono::duration<long int, std::ratio<1, 1000000000> > >::operator=(std::chrono::time_point<std::chrono::_V2::steady_clock, std::chrono::duration<long int, std::ratio<1, 1000000000> > >&&)
/usr/include/c++/7.2.1/chrono:610:14: note: no known conversion for argument 1 from ‘std::chrono::_V2::system_clock::time_point {aka std::chrono::time_point<std::chrono::_V2::system_clock, std::chrono::duration<long int, std::ratio<1, 1000000000> > >}’ to ‘std::chrono::time_point<std::chrono::_V2::steady_clock, std::chrono::duration<long int, std::ratio<1, 1000000000> > >&&’